1. Field of the Invention
The present invention relates to novel cyclohexane derivatives containing carboxyl groups of formula (I): ##STR3## in which the substituents, --Z--COOR).sub.n and --CH.dbd.CH.sub.2).sub.3-n, are in the 1-, 2-, and 4-positions of the cyclohexane ring, Z is a --CH.sub.2 --CH.sub.2 -- group (ethylene group) or a ##STR4## group (ethylidene group), R is an alkyl group having 1 to 10 carbon atoms, and n is an integer of 1 to 3, and mixtures thereof; a method for producing such cyclohexane derivatives; and polymers prepared from such cyclohexane derivatives.
2. Discussion of the Background
Cyclohexane derivatives containing carboxyl groups are of great interest as monomers and comonomers for the production of polymers. 1,2,4-trivinylcyclohexane, which is used as a starting material in the method according to the present invention, can be obtained, for example, according to R. Rienacker, Brennstoff-Chemie, vol. 45, p. 206 (1964), by pyrolysis of 1,5,9-cylcododecatriene.
According to DE-B 29 12 489, monoolefins with an internal carbon-carbon double bond can be hydrocarboxyalkylated in the presence of a cobalt compound as the catalyst and pyridine or a non-ortho-alkylated pyridine as the promoter, at a termperature of 165.degree. to 195.degree. C. and a pressure of 150,000 to 300,000 hPa (hectopascals). However, this reference provides no information concerning the behavior of dienes or polyenes under these conditions.
J. Falbe, Synthesen mit Kohlenmonoxid, Berlin - Heidelberg - New York, 1967, states that 1,5-cyclooctadiene is hydrocarboxyalkylated either to an unsaturated monocarboxylic acid ester or to a saturated dicarboxylic acid ester with a palladium catalyst. In the analogous hydrocarboxylation of 1,5-cyclooctadiene with a cobalt catalyst, however, only a saturated monocarboxylic acid is obtained. Therefore, of the two internal double bonds, one is hydrocarboxylated and one is hydrogenated on the cobalt catalyst.
According to U. Buller (dissertation, Technical University of Rhineland-Westphalia in Aachen, 1980), .alpha.,.omega.-dienes react with carbon monoxide and an alcohol at 130.degree. to 140.degree. C. to form dicarboxylic acid esters, with high selectivity.
In DE-A 38 12 184, reactive .alpha.,.omega.-dienes are hydrocarboxyalkylated on cobalt catalysts. Here, .omega.-enecarboxylic acid esters are obtained at 100.degree. to 200.degree. C. and 150,000 to 350,000 hPa. Therefore, only one of the terminal position double bonds is hydrocarboxyalkylated, and one double bond is retained. However, the conversion yields of the .alpha.,.omega.-dienes are always below 50% in the examples.
Accordingly, prior to the present invention, it was not known that terminal position trienes could be hydrocarboxyalkylated. It was also unknown what products hydrocarboxyalkylation of such trienes would yield.
Thus, there remains a need for cyclohexane derivatives which contain carboxyl groups. These also remains a need for a method which produces cyclohexane derivatives which contain carboxyl groups.